1. Field of the Invention
The invention relates to a ratchet screwdriver, more particularly to a ratchet mechanism housing assembly of a ratchet screwdriver which can permit the generation of a larger torsional force than the prior art.
2. Description of the Related Art
Ratchet screwdrivers are known in the art. An example of such a screwdriver has been disclosed in U.S. Pat. No. 4,621,718 and comprises a ratchet mechanism housing assembly which includes a drive shaft that has a ratchet wheel mounted thereon and an elongated housing that has an axially extending cavity with a closed end and an open end opposite the closed end, and an axially extending peripheral slot formed therein. The drive shaft extends into the cavity via the open end such that the ratchet wheel is positioned operatively within the housing at a point about midway along the length of the peripheral slot. Two ratchet pawls are positioned in the peripheral slot to engage selectively the teeth of the ratchet wheel so as to provide forward, reverse or combination drive in a conventional manner. The ratchet pawls are selectively engaged with and disengaged from the ratchet wheel by means of a slidable thumb actuator which is positioned operatively within the peripheral slot.